Communication method and apparatus

Abstract

A communication method and apparatus are provided. The method includes: A terminal device receives a downlink reference signal from an access network device, and the terminal device sends first indication information to the access network device, where the first indication information indicates at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases. According to the foregoing method, the at least one Doppler shift is indicated by using the first indication information, so that there is no need to feed back all Doppler shifts determined based on the downlink reference signal.

What is claimed is: 
     
         1 . A communication method, comprising:
 receiving, by a terminal device, a downlink reference signal from an access network device; and   sending, by the terminal device, first indication information to the access network device, wherein the first indication information indicates at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases.   
     
     
         2 . The method according to  claim 1 , wherein that the first indication information indicates at least one Doppler shift comprises:
 the first indication information indicates the at least one Doppler shift by indicating an index of a Doppler domain basis corresponding to the Doppler shift, or the first indication information indicates the at least one Doppler shift by indicating a value of the Doppler shift.   
     
     
         3 . The method according to  claim 2 , wherein the at least one Doppler shift is one or more groups of Doppler shifts, each group of the one or more groups of Doppler shifts comprises at least two Doppler shifts, the at least two Doppler shifts are consecutive, and that the at least two Doppler shifts are consecutive means that indexes of Doppler domain bases corresponding to the Doppler shifts are consecutive or values of the Doppler shifts have a same interval. 
     
     
         4 . The method according to  claim 3 , wherein for each group of Doppler shifts, the first indication information indicates indexes of two Doppler domain bases, and the indexes of the two Doppler domain bases are respectively an index with a largest value and an index with a smallest value in indexes of Doppler domain bases corresponding to the group of Doppler shifts. 
     
     
         5 . The method according to  claim 3 , wherein for each group of Doppler shifts, the first indication information indicates an index of one Doppler domain basis and an index length value, and the index of the Doppler domain basis and the index length value are used to determine each Doppler shift in the group of Doppler shifts. 
     
     
         6 . The method according to  claim 5 , wherein the index of the Doppler domain basis is an index with a largest value or an index with a smallest value in indexes of Doppler domain bases corresponding to the group of Doppler shifts. 
     
     
         7 . The method according to  claim 3 , wherein for each group of Doppler shifts, the first indication information indicates an index length value of one Doppler domain basis, the index length value and an index of one Doppler domain basis are used to determine each Doppler shift in the group of Doppler shifts, and the index of the Doppler domain basis is pre-defined, or the index of the Doppler domain basis is indicated by using fourth indication information. 
     
     
         8 . The method according to  claim 3 , wherein for each group of Doppler shifts, the first indication information indicates values of two Doppler shifts, and the values of the two Doppler shifts are respectively a largest value and a smallest value of the Doppler shifts in the group of Doppler shifts. 
     
     
         9 . The method according to  claim 3 , wherein for each group of Doppler shifts, the first indication information indicates a value of one Doppler shift and a value span, and the value of the Doppler shift and the value span are used to determine each Doppler shift in the group of Doppler shifts. 
     
     
         10 . The method according to  claim 9 , wherein the value of the Doppler shift is a largest value or a smallest value in the group of Doppler shifts. 
     
     
         11 . A communication method, comprising:
 sending, by an access network device, a downlink reference signal to a terminal device; and   receiving, by the access network device, first indication information from the terminal device, wherein the first indication information indicates at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases.   
     
     
         12 . The method according to  claim 11 , wherein that the first indication information indicates at least one Doppler shift comprises:
 the first indication information indicates the at least one Doppler shift by indicating an index of a Doppler domain basis corresponding to the Doppler shift, or the first indication information indicates the at least one Doppler shift by indicating a value of the Doppler shift.   
     
     
         13 . The method according to  claim 12 , wherein the at least one Doppler shift is one or more groups of Doppler shifts, each group of the one or more groups of Doppler shifts comprises at least two Doppler shifts, the at least two Doppler shifts are consecutive, and that the at least two Doppler shifts are consecutive means that indexes of Doppler domain bases corresponding to the Doppler shifts are consecutive or values of the Doppler shifts have a same interval. 
     
     
         14 . The method according to  claim 13 , wherein for each group of Doppler shifts, the first indication information indicates indexes of two Doppler domain bases, and the indexes of the two Doppler domain bases are respectively an index with a largest value and an index with a smallest value in indexes of Doppler domain bases corresponding to the group of Doppler shifts. 
     
     
         15 . The method according to  claim 13 , wherein for each group of Doppler shifts, the first indication information indicates an index of one Doppler domain basis and an index length value, and the index of the Doppler domain basis and the index length value are used to determine each Doppler shift in the group of Doppler shifts. 
     
     
         16 . The method according to  claim 15 , wherein the index of the Doppler domain basis is an index with a largest value or an index with a smallest value in indexes of Doppler domain bases corresponding to the group of Doppler shifts. 
     
     
         17 . The method according to  claim 13 , wherein for each group of Doppler shifts, the first indication information indicates an index length value of one Doppler domain basis, the index length value and an index of one Doppler domain basis are used to determine each Doppler shift in the group of Doppler shifts, and the index of the Doppler domain basis is pre-defined, or the index of the Doppler domain basis is indicated by using fourth indication information. 
     
     
         18 . An apparatus, comprising:
 a memory storing instructions; and   at least one processor in communication with the memory, the at least one processor configured, upon execution of the instructions, to perform the following steps:   receiving a downlink reference signal from an access network device; and   sending first indication information to the access network device, wherein the first indication information indicates at least one Doppler shift, the at least one Doppler shift is determined based on the downlink reference signal, and the at least one Doppler shift is associated with at least two frequency domain bases.   
     
     
         19 . The apparatus according to  claim 18 , wherein that the first indication information indicates at least one Doppler shift comprises:
 the first indication information indicates the at least one Doppler shift by indicating an index of a Doppler domain basis corresponding to the Doppler shift, or the first indication information indicates the at least one Doppler shift by indicating a value of the Doppler shift.   
     
     
         20 . The apparatus according to  claim 19 , wherein the at least one Doppler shift is one or more groups of Doppler shifts, each group of the one or more groups of Doppler shifts comprises at least two Doppler shifts, the at least two Doppler shifts are consecutive, and that the at least two Doppler shifts are consecutive means that indexes of Doppler domain bases corresponding to the Doppler shifts are consecutive or values of the Doppler shifts have a same interval.